Charlie Chaplin was exception not rule

Julio Iglesias senior was reportedly 89, Charlie Chaplin, 73 and Rod Stewart a relative youngster at 60 when they became fathers. But now the myth of man's supposed fertilty unto the grave has been punctured by research from France.

In fact, a man's fertility appears to decline after the age of 40, in much the same way that a woman's ability to conceive fades after 35. The study, of nearly 2,000 couples undergoing fertility treatment, found that pregnancy attempts were 70% more likely to fail when the man was age 40 or older than if he were younger than 30 — regardless of his wife's age.

Because all the women in the study were completely sterile and undergoing in vitro fertilization (IVF), the age of the fathers was key. And while past studies have suggested that older men are less likely to father children, the extent to which this was related to biological changes or to decreased sexual activity has been unclear.

'Our results provide, for the first time, strong evidence for a paternal age effect on failure to conceive that is linked only to biological male aging,' the study authors report in the journal Fertility and Sterility.

Dr. Elise de La Rochebrochard of the French national health institute INSERM concluded that 'in reproduction, age must no longer be considered as the concern of the woman, but as that of the couple.'